Question 1

According to the Fick equation, what could cause the C(a- v)O₂ to decrease?

Accepted Answer

High cardiac output can decrease the arteriovenous oxygen difference (C(a-v)O2) because the blood flows more quickly through the tissues, allowing less time for oxygen extraction.

Question 2

Which of the following make up the peripheral component of afterload?
1) The radius of the vessels
2) The length of the vessels
3) The viscosity of the blood
4) The elasticity or compliance of the vessels

Accepted Answer

The peripheral component of afterload is influenced by the radius of the vessels, the viscosity of the blood, and the elasticity or compliance of the vessels. These factors affect the resistance the heart must overcome to eject blood.

Question 3

The filling pressure of the right heart is also known as the _____ pressure.

Accepted Answer

The filling pressure of the right heart is known as the central venous pressure, which reflects the amount of blood returning to the heart and the ability of the heart to pump the blood into the arterial system.

Question 4

Positive-pressure ventilation with positive end-expiratory pressure (PEEP) has what effect on afterload?

Accepted Answer

The answer of Positive-pressure ventilation with positive end-expiratory pressure (PEEP)...

Question 5

The resistance to ventricular ejection also is known as:

Accepted Answer

Afterload is the term used to describe the resistance the heart must overcome to eject blood during systole.

Question 6

When the Fick method is used to calculate cardiac output, if C(a - v)O₂ is greater than expected and VO₂ is normal, cardiac output probably will be:

Accepted Answer

If the arteriovenous oxygen difference (C(a - v)O2) is greater than expected and oxygen consumption (VO2) is normal, it suggests that the cardiac output is less than expected. This is because a larger difference indicates that more oxygen is being extracted by the tissues, which typically occurs when blood flow (cardiac output) is reduced.

Question 7

To obtain the coronary perfusion pressure, what two values are needed?

Accepted Answer

Coronary perfusion pressure is calculated using diastolic blood pressure and pulmonary capillary wedge pressure.

Question 8

The filling pressure of the left heart is also known as the _____ pressure.

Accepted Answer

The filling pressure of the left heart is known as the pulmonary capillary wedge pressure, which reflects the pressure in the left atrium.

Question 9

A drug that increases the contractility of the heart is known as a positive:

Accepted Answer

A positive inotrope is a drug that increases the force of heart muscle contraction, thereby increasing the contractility of the heart.

Question 10

Why has use of the pulmonary artery catheter diminished in many ICUs?

Accepted Answer

Some studies and expert opinions suggest that the use of pulmonary artery catheters may not improve outcomes and could potentially increase mortality rates, leading to a decline in their use in many ICUs.

Question 11

What effect does spontaneous deep inspiration have on venous return?

Accepted Answer

Spontaneous deep inspiration decreases intrathoracic pressure, which enhances venous return to the heart by increasing the pressure gradient between the peripheral veins and the right atrium.

Question 12

When ventricular function curves are performed on a patient with a suspected failing left ventricle, how does cardiac output typically change as the pulmonary capillary wedge pressure increases?

Accepted Answer

In a failing left ventricle, as pulmonary capillary wedge pressure increases, cardiac output initially increases due to the Frank-Starling mechanism but eventually decreases as the heart becomes unable to handle the increased preload, leading to heart failure.

Question 13

What effect does an increase in intrathoracic pressure have on venous return?

Accepted Answer

An increase in intrathoracic pressure decreases the pressure gradient between the veins and the right atrium, thereby reducing venous return.

Question 14

Which of the following is used to determine the afterload of the right ventricle?

Accepted Answer

The answer of Which of the following is used to...

Question 15

When ventricular function curves are performed on a patient with a suspected failing right ventricle, how does cardiac output typically change as central venous pressure increases?

Accepted Answer

Cardiac output increases at first as central venous pressure increases, but then decreases as the right ventricle fails.

Question 16

Positive-pressure ventilation with PEEP has what effect on preload?

Accepted Answer

Positive-pressure ventilation with PEEP increases intrathoracic pressure, which can decrease venous return to the heart, thereby dampening preload.

Question 17

The greatest determinant of peripheral resistance to blood flow is:

Accepted Answer

The radius of the vessels is the greatest determinant of peripheral resistance due to its exponential effect on resistance, as described by Poiseuille's law.

Question 18

Which of the following may cause a decrease in ventricular compliance?
1) Inotropic drugs
2) Vasodilator drugs
3) Myocardial infarction
4) Positive end-expiratory pressure

Accepted Answer

Myocardial infarction can lead to scarring and stiffening of the heart muscle, reducing compliance. Positive end-expiratory pressure can increase intrathoracic pressure, affecting ventricular filling and compliance. Inotropic drugs generally increase contractility but do not directly decrease compliance.

Question 19

What method of measuring cardiac output is most popular in intensive care units (ICUs) around the country?

Accepted Answer

Thermodilution is the most popular method for measuring cardiac output in ICUs, often using a pulmonary artery catheter (Swan-Ganz catheter).

Question 20

Which of the following can cause an increase in pulmonary vascular resistance?
1) Exercise
2) Acidosis
3) Hypoxemia
4) Release of histamine because of allergic response

Accepted Answer

Acidosis, hypoxemia, and the release of histamine due to an allergic response can all lead to an increase in pulmonary vascular resistance. Acidosis and hypoxemia cause vasoconstriction in the pulmonary circulation, while histamine can cause bronchoconstriction and increase vascular resistance.

Quiz 16: Assessment of Hemodynamic Pressures

According to the Fick equation, what could cause the C(a- v) O₂ to decrease?

Which of the following make up the peripheral component of afterload? 1) The radius of the vessels 2) The length of the vessels 3) The viscosity of the blood 4) The elasticity or compliance of the vessels

The filling pressure of the right heart is also known as the _____ pressure.

Positive-pressure ventilation with positive end-expiratory pressure (PEEP) has what effect on afterload?

The resistance to ventricular ejection also is known as:

When the Fick method is used to calculate cardiac output, if C(a - v) O₂ is greater than expected and VO₂ is normal, cardiac output probably will be:

To obtain the coronary perfusion pressure, what two values are needed?

The filling pressure of the left heart is also known as the _____ pressure.

A drug that increases the contractility of the heart is known as a positive:

Why has use of the pulmonary artery catheter diminished in many ICUs?

What effect does spontaneous deep inspiration have on venous return?

When ventricular function curves are performed on a patient with a suspected failing left ventricle, how does cardiac output typically change as the pulmonary capillary wedge pressure increases?

What effect does an increase in intrathoracic pressure have on venous return?

Which of the following is used to determine the afterload of the right ventricle?

When ventricular function curves are performed on a patient with a suspected failing right ventricle, how does cardiac output typically change as central venous pressure increases?

Positive-pressure ventilation with PEEP has what effect on preload?

The greatest determinant of peripheral resistance to blood flow is:

Which of the following may cause a decrease in ventricular compliance? 1) Inotropic drugs 2) Vasodilator drugs 3) Myocardial infarction 4) Positive end-expiratory pressure

What method of measuring cardiac output is most popular in intensive care units (ICUs) around the country?

Which of the following can cause an increase in pulmonary vascular resistance? 1) Exercise 2) Acidosis 3) Hypoxemia 4) Release of histamine because of allergic response

Quiz 16: Assessment of Hemodynamic Pressures

According to the Fick equation, what could cause the C(a- v) O2 to decrease?

Which of the following make up the peripheral component of afterload? 1) The radius of the vessels 2) The length of the vessels 3) The viscosity of the blood 4) The elasticity or compliance of the vessels

The filling pressure of the right heart is also known as the _____ pressure.

Positive-pressure ventilation with positive end-expiratory pressure (PEEP) has what effect on afterload?

The resistance to ventricular ejection also is known as:

When the Fick method is used to calculate cardiac output, if C(a - v) O2 is greater than expected and VO2 is normal, cardiac output probably will be:

To obtain the coronary perfusion pressure, what two values are needed?

The filling pressure of the left heart is also known as the _____ pressure.

A drug that increases the contractility of the heart is known as a positive:

Why has use of the pulmonary artery catheter diminished in many ICUs?

What effect does spontaneous deep inspiration have on venous return?

When ventricular function curves are performed on a patient with a suspected failing left ventricle, how does cardiac output typically change as the pulmonary capillary wedge pressure increases?

What effect does an increase in intrathoracic pressure have on venous return?

Which of the following is used to determine the afterload of the right ventricle?

When ventricular function curves are performed on a patient with a suspected failing right ventricle, how does cardiac output typically change as central venous pressure increases?

Positive-pressure ventilation with PEEP has what effect on preload?

The greatest determinant of peripheral resistance to blood flow is:

Which of the following may cause a decrease in ventricular compliance? 1) Inotropic drugs 2) Vasodilator drugs 3) Myocardial infarction 4) Positive end-expiratory pressure

What method of measuring cardiac output is most popular in intensive care units (ICUs) around the country?

Which of the following can cause an increase in pulmonary vascular resistance? 1) Exercise 2) Acidosis 3) Hypoxemia 4) Release of histamine because of allergic response

According to the Fick equation, what could cause the C(a- v) O₂ to decrease?

When the Fick method is used to calculate cardiac output, if C(a - v) O₂ is greater than expected and VO₂ is normal, cardiac output probably will be: